JP2018108884A - Paper sheet thickness detection device and image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and accurately detect the thickness of a conveyed sheet in an image forming apparatus or the like by a sheet thickness detecting device.
SOLUTION: A sheet thickness detecting device 30 for detecting the thickness of a sheet S to be conveyed is paired with a pair of rollers 31a and 32a provided to face each other so as to sandwich the sheet S to be conveyed. Further, the shafts 31b and 32b for holding the rollers 31a and 32a, the biasing means 34 for biasing one shaft 32b in a direction approaching the other shaft 31a, and the shaft 32b biased by the biasing means 34 The pair of rollers 31a is made of a soft member, and the pair of rollers 31a and 32a is arranged at a position where the end surface of the paper S being conveyed is not sandwiched. I let you.
[Selection] Figure 4

Description

  The present invention relates to a sheet thickness detection device that detects the thickness of a sheet being conveyed and an image forming apparatus including such a sheet thickness detection device. In particular, the present invention is characterized in that the thickness of the sheet being conveyed can be accurately detected with a simple configuration.

  Conventionally, in image forming apparatuses such as copiers, printers, facsimiles, and composite machines of these, the type of paper used for forming images on paper has not been fixed. Those having different thicknesses (basis weights) are used.

  Here, when using papers having different thicknesses (basis weights) and the like, conditions for image formation, for example, transfer conditions such as a transfer current when a toner image is transferred to the paper, The fixing conditions such as the fixing temperature when fixing the toner image transferred on the paper to the paper are changed.

  In recent years, as disclosed in Patent Documents 1 and 2, there has been proposed an apparatus that automatically detects the thickness of a sheet during conveyance of a sheet on which image formation is performed.

  Here, in what is shown in Patent Document 1, in a roller pair composed of a driving roller and a driven roller (displacement roller) that pinches and conveys a sheet, the shaft of the driving roller is rotatable and does not move in the radial direction. In addition, the thickness of the paper on the shaft of the driven roller is supported by the roller portion of the driven roller rotatably supported by the shaft of the driven roller. A contact-type displacement sensor that detects the amount of displacement in the vertical direction is provided, and the sheet thickness is detected by a detection signal of the contact-type displacement sensor.

  Moreover, in what is shown by patent document 2, it arrange | positions in the position which respectively opposes the 3 or more 1st roller arranged in the direction orthogonal to the conveyance direction of a paper, and the 3 or more 1st roller. Three or more second rollers, a first roller shaft that supports only two first rollers of the three or more first rollers, and one or more that supports the three or more second rollers, or Two or more second roller shafts, one or more third roller shafts supporting the remaining first rollers of the three or more first rollers, and the first roller shafts A first roller shaft support member that supports the two roller shafts so as to be displaceable in a contact / separation direction, a biasing unit that biases the first roller shaft in a direction approaching the second roller shaft, and the contact / separation direction Displacement of the first roller shaft Displacement amount detection means for detecting the thickness of the sheet material conveyed in a state of being sandwiched between the first roller and the second roller based on the detection result of the displacement amount detection means. I try to detect it.

  However, in the above-described Patent Documents 1 and 2, the relationship between the position of the conveyed paper and the position of the roller for detecting the thickness of the paper is not considered, and the thickness of the paper is not considered. When the roller for detection sandwiches the end surface of the paper, the roller is partially deformed and the shaft holding the roller is inclined, and as a result, the thickness of the paper is accurately detected. There was a problem that it was impossible.

JP 2012-166913 A JP2015-13719A

  An object of the present invention is to solve the above-described problem in detecting the thickness of a sheet being conveyed, and a roller for detecting the thickness of the sheet pinches an end surface of the sheet. It is an object of the present invention to prevent such a situation and accurately detect the thickness of a sheet being conveyed with a simple configuration.

  In the paper thickness detection device according to the present invention, in order to solve the above-described problem, in the paper thickness detection device that detects the thickness of the paper being conveyed, the paper thickness detection device is provided facing the paper to be conveyed. A pair of rollers, each shaft that holds the pair of rollers, a biasing means that biases one shaft closer to the other shaft, and biased by the biasing means A displacement sensor that detects the amount of shaft displacement is provided, and the pair of rollers is made of a soft member, and the pair of rollers is arranged at a position where the end face of the conveyed paper is not sandwiched. .

  As described above, when the pair of rollers provided to face each other so as to sandwich the paper to be transported is disposed at a position where the end surface of the paper to be transported is not sandwiched, the pair of rollers is transported. The roller is partially deformed by sandwiching the end surface of the paper to be formed, and the shaft holding the roller is prevented from being inclined, and the shafts of the paired rollers are paralleled by the biasing means. In this state, the displacement is accurately detected by the displacement sensor, and the thickness of the conveyed paper can be accurately detected.

  Here, in the paper thickness detection device, the other roller with respect to the one roller constituted by the soft member is constituted by a hard member, and the width of the roller constituted by the hard member is constituted by a soft member. It is preferable to make it larger than the width of the roller. Thus, when the width of the roller configured with the hard member is larger than the width of the roller configured with the soft member, the roller configured with the hard member with respect to the entire width direction of the roller configured with the soft member. A uniform pressure is applied to the roller so that the roller made of a soft member is uniformly deformed. In addition, if a roller made of a hard member is used for each of the rollers facing each other, the rollers are likely to repel each other, and the amount of displacement of the shaft holding the roller can be accurately determined by the influence of mechanical vibration or the like. If a roller made of a soft material is used for each of the opposing rollers, the positions in the width direction of the rollers are exactly matched due to the effects of component accuracy and assembly accuracy. It is difficult to dispose the roller, and the roller made of soft material will be uneven. It becomes difficult to detect accurately.

  In the paper thickness detecting device, the shaft of the roller constituted by the hard member is movably provided toward the shaft of one roller constituted by the soft member, and the hard member is provided by the biasing means. The displacement of the roller shaft composed of a hard member urged by the urging means is urged toward the shaft of one roller composed of a soft member. It can be made to detect by. In this case, when the conveyed paper passes between a roller made of a hard member and a roller made of a soft member, the amount of displacement of the shaft of the roller made of a hard member due to the thickness of the paper Can be appropriately detected by the displacement sensor.

  In the paper thickness detecting device, only the roller constituted by the hard member can be rotated without rotating the shaft of the roller constituted by the hard member. In this way, if the shaft of the roller composed of a hard member is not rotated, when the displacement sensor detects the amount of displacement of the roller shaft composed of a hard member, the contact type displacement sensor is used. The shaft of the roller made of a hard member is not worn or rattled by contact with the displacement sensor, and the displacement amount of the shaft of the roller made of a hard member is properly detected by the displacement sensor. become able to.

  In the paper thickness detection device, one roller made of a soft member that holds the paper to be conveyed is arranged inside the minimum size of the paper. In this way, even when detecting the thickness of the minimum size paper, one roller made of a soft member sandwiches the end surface of the minimum size paper, and the roller made of a soft member partially deforms Thus, the shaft holding the roller is prevented from being inclined, and the thickness of the minimum size paper can be detected appropriately.

  In the paper thickness detection device, it is preferable that two pairs of rollers provided to face each other so as to sandwich the conveyed paper are arranged in the axial direction with a predetermined interval therebetween. . If it does in this way, it will become possible to arrange | position the axis | shaft in each roller in parallel stably, and the roller which became the pair provided oppositely contacts in two positions via a required space | interval in each axial direction. . In the case where two rollers paired in this way are arranged in the respective axial directions with a required interval, the two displacement sensors are arranged in the axial direction with a required interval. If it is provided at a position between the two, the displacement sensor can be made less susceptible to the influence of the inclination of the shaft when detecting the displacement amount of the shaft, and the accuracy of detecting the thickness of the paper can be further improved.

  In the paper thickness detection device, the urging means may be provided at both ends of the shaft for detecting the displacement amount of the shaft by the displacement sensor. In this way, the shaft that detects the amount of displacement of the shaft is stably urged toward the other shaft facing the roller, and the roller provided on the shaft that detects the amount of displacement is changed to the roller provided on the other shaft. It can be pressed stably, and the accuracy of detecting the thickness of the paper can be further improved.

  In the image forming apparatus according to the present invention, the above-described sheet thickness detecting device is used. Here, in the image forming apparatus of the present invention, it is possible to detect the thickness of a sheet on which an image is formed by feeding by a sheet feeding device, using the above-described sheet thickness detecting device, and automatic document reading In the image forming apparatus provided with the apparatus, the thickness of the sheet to be a document fed by the automatic document reader can be detected by using the sheet thickness detecting device.

  In the paper thickness detection device according to the present invention, the pair of rollers provided to face each other so as to sandwich the paper to be transported as described above are arranged so as not to sandwich the end face of the paper to be transported. Therefore, the paired rollers are sandwiched between the end surfaces of the paper to be conveyed, the rollers are partially deformed, and the shaft holding this roller is prevented from being inclined, The shaft of the roller thus formed is urged in a parallel state by the urging means, and the displacement amount of the shaft can be accurately detected by the displacement sensor.

  As a result, in the sheet thickness detection device according to the present invention, the thickness of the sheet being conveyed can be accurately detected with a simple configuration.

1 is a schematic explanatory diagram illustrating an image forming apparatus configured to detect the thickness of a sheet on which image formation is performed by a sheet thickness detection apparatus in an embodiment of the present invention. FIG. 3 is a partial schematic perspective view showing a paper thickness detection device that detects the thickness of the paper in the embodiment. FIG. 3 is a partial schematic explanatory view showing a paper thickness detection device that detects the thickness of the paper in the embodiment. FIG. 3 is a partial schematic explanatory view showing a state in which the thickness of the sheet is detected by the sheet thickness detecting device in the embodiment.

  Next, a sheet thickness detection apparatus and an image forming apparatus according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. The sheet thickness detection apparatus and the image forming apparatus according to the present invention are not limited to those shown in the following embodiments, and can be implemented with appropriate modifications within a range that does not change the gist thereof.

  In the image forming apparatus 1 according to the embodiment of the present invention, as shown in FIG. 1, a document sheet (not shown) is automatically fed onto an image forming apparatus body 1a that forms an image on a sheet S. Thus, an automatic document reader 1b for reading the contents of the document sheet is provided.

  In the image forming apparatus main body 1a, four imaging cartridges 10A to 10D are mounted.

  Here, in each of the imaging cartridges 10A to 10D, the photosensitive member 11, the charging device 12 for charging the surface of the photosensitive member 11, and the surface of the charged photosensitive member 11 are exposed according to image information. A latent image forming device 13 for forming an electrostatic latent image on the surface of the photoconductor 11, a developing device 14 for supplying toner to the electrostatic latent image formed on the surface of the photoconductor 11 to form a toner image, A first cleaning device 15 is provided for removing toner remaining after the toner image formed on the surface of the photoconductor 11 is transferred to the intermediate transfer belt 22 from the surface of the photoconductor 11.

  In the developing devices 14 in the imaging cartridges 10A to 10D, toners of different colors are accommodated, and black, yellow, magenta, and cyan toners are accommodated.

  In the image forming apparatus main body 1a, in each of the imaging cartridges 10A to 10D, the surface of the photoconductor 11 is charged by the charging device 12, and the surface of the photoconductor 11 thus charged is respectively charged. The latent image forming device 13 performs exposure according to the image information to form an electrostatic latent image according to the image information on the surface of each photoconductor 11, and thus the static image formed on the surface of each photoconductor 11. The toner of each color is supplied to the electrostatic latent image from each of the developing devices 14 to form a toner image of each color on the surface of each photoconductor 11.

  Next, the toner image of each color formed on the surface of each photoconductor 11 in each imaging cartridge 10 </ b> A to 10 </ b> D is spanned between the driving roller 21 a and the rotating roller 21 b and is driven to rotate. The toner image is sequentially transferred onto the intermediate transfer belt 22 by the primary transfer roller 23 to form a synthesized toner image on the intermediate transfer belt 22. The toner image thus formed is then transferred to the secondary transfer roller 22 by the intermediate transfer belt 22. The toner remaining on the surface of each photoconductor 11 after transfer is removed from the surface of each photoconductor 11 by the corresponding first cleaning device 15 while being guided to a position opposed to 24.

  Further, in the image forming apparatus main body 1a, the paper S accommodated in the paper feed cassette 25 provided in the lower part is fed by the paper feed roller 25a, and the fed paper S is fed with the paper feed roller 25a. The sheet S is guided between the facing roller 25b provided opposite to the sheet roller 25a and the sheet roller 25b is passed through the sheet roller 25a. The sheet S is fed between the pair of timing rollers 26. I try to guide you.

  Then, the sheet S is guided between the intermediate transfer belt 22 and the secondary transfer roller 24 at an appropriate timing by the timing roller 26, and the toner image formed on the intermediate transfer belt 22 is subjected to secondary transfer. The image is transferred onto the paper S by the roller 24. In addition, toner and other residues that are not transferred to the sheet S and remain on the intermediate transfer belt 22 are removed from the intermediate transfer belt 22 by the second cleaning device 27.

  Next, the sheet S on which the toner image is transferred as described above is guided to a fixing device 28 having a pair of heat-fixing rollers. In this fixing device 28, the unfixed toner image transferred to the sheet S is transferred to the sheet. The sheet S on which the toner image is fixed in this manner is guided between a pair of conveying rollers 29 provided on the paper discharge side, and the sheet S on which the toner image is fixed by the conveying roller 29 is guided. Paper is discharged from the image forming apparatus main body 1a.

  In the present embodiment, the sheet for detecting the thickness of the sheet S sent in this way to a position in the middle of feeding the sheet S fed by the sheet feeding roller 25a to the timing roller 26 as described above. A thickness detection device 30 is provided, and information on the thickness of the paper S detected by the paper thickness detection device 30 is output to the control device X. The toner image formed on the intermediate transfer belt 22 by the control device X is provided. The transfer current when the toner image is transferred onto the sheet S by the secondary transfer roller 24, the fixing temperature at which the unfixed toner image transferred by the fixing device 28 is heated and fixed on the sheet S, and the like are controlled.

  Next, the paper thickness detection device 30 in the present embodiment will be specifically described with reference to FIGS.

  In the paper thickness detection device 30 in the present embodiment, a first roller member 31 and a second roller member 32 that sandwich the paper S to be transported are provided to detect the thickness of the paper S to be transported. .

  Here, as the first roller member 31, the first roller 31 a made of rubber, which is a soft member, is rotated together with the rotating first shaft 31 b in the axial direction. Two are provided at a required interval.

  On the other hand, as the second roller member 32, the second roller 32a made of a resin harder than the first roller 31a is required in the axial direction so as to be rotatable with respect to the second shaft 32b that does not rotate. Two are provided at intervals.

  And each 1st roller 31a comprised with the rubber in the said 1st roller member 31 and each 2nd roller 32a comprised with the resin in the 2nd roller member 32 are arrange | positioned so as to oppose. In addition, the width d2 of the second roller 32a is larger than the width d1 of the first roller 31a.

  Further, the second shaft 32b of the second roller member 32 is held by the holding members 33 provided outside the second rollers 32a, and the holding members 33 are respectively compressed coil springs. The urging means 34 is configured to urge the first roller member 31 toward the first shaft 31b so that the second shaft 32b of the second roller member 32 is moved to the holding members. The first roller member 31 can be moved toward the first shaft 31 b along the guide hole 33 a provided in 33.

  Further, in the second roller member 32, in order to detect the displacement amount of the second shaft 32b at the position of the second shaft 32b between the second rollers 32a provided through a required interval. The contact type displacement sensor 35 is provided.

  Then, as shown in FIG. 4, the sheet S fed as described above includes each first roller 31 a in the first roller member 31 and each second roller 32 a in the second roller member 32. , The second shaft 32b holding the second roller 32a of the second roller member 32 rotatably is pushed by the sheet S, and the second shaft 32b is It is displaced in the direction away from the first roller member 31 along the guide hole 33a provided in the holding member 33 against the urging means 34, and the displacement amount of the second shaft 32b is set as described above. It is detected by the displacement sensor 35, and based on this, the thickness of the paper S is detected.

  Here, in the sheet thickness detection device 30 according to the present embodiment, the pair of first rollers 31a provided at least on the first shaft 31b of the first roller member 31 with a required interval are provided as described above. As described above, even if the paper S is the smallest size, the end face of the paper S is positioned inside the smallest paper S guided between the first rollers 31a and the second rollers 32a. The first roller 31a is prevented from being sandwiched, and each first roller 31a is partially deformed to prevent the first shaft 31b from being inclined and the like. Even for the paper S, its thickness can be appropriately detected.

  In the sheet thickness detection device 30 according to the present embodiment, the contact-type displacement sensor 35 is used to detect the displacement of the position of the second shaft 32b in the second roller member 32. A displacement sensor 35 of the formula can also be used.

  In the present embodiment, the sheet thickness detection device 30 is provided in the image forming apparatus main body 1a in the image forming apparatus 1 as described above, but it can also be provided in the automatic document reading apparatus 1b.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus, 1a Image forming apparatus main body, 1b Automatic document reader 10A, 10B, 10C, 10D Imaging cartridge 11 Photoconductor 12 Charging apparatus 13 Latent image forming apparatus 14 Developing apparatus 15 1st cleaning apparatus 21a Drive roller, 21b Rotation Roller 22 Intermediate transfer belt 23 Primary transfer roller 24 Secondary transfer roller 25 Paper feed cassette 25a Paper feed roller, 25b Rolling roller 26 Timing roller 27 Second cleaning device 28 Fixing device 29 Transport roller 30 Paper thickness detection device 31 First roller Member 31a first roller 31b first shaft 32 second roller member 32a second roller 32b second shaft 33 holding member 33a guide hole 34 biasing means 35 displacement sensor S paper X control device d1 of the first roller d2 the width of the second roller

Claims (9)

In the paper thickness detection device that detects the thickness of the paper being conveyed,
A pair of rollers provided facing each other so as to sandwich the conveyed paper, each shaft holding each of the paired rollers, and a biasing force in a direction to bring one shaft closer to the other shaft And a displacement sensor that detects the amount of displacement of the shaft urged by the urging means, and the paired rollers are made of a soft member and convey the paired rollers A sheet thickness detecting apparatus, wherein the sheet thickness detecting apparatus is disposed at a position where the end face of the sheet to be sandwiched is not sandwiched.   The paper thickness detection apparatus according to claim 1, wherein the other roller with respect to the one roller configured with the soft member is configured with a hard member, and the width of the roller configured with the hard member is configured with a soft member. A paper thickness detection device characterized in that it is larger than the width of the roller.   3. The paper thickness detecting device according to claim 2, wherein a shaft of the roller configured by the hard member is movably provided toward a shaft of the roller configured by the soft member, and the hard member is configured by the biasing unit. The roller shaft constituted by the above is urged toward the roller shaft constituted by the soft member, and the displacement amount of the roller shaft constituted by the hard member urged by the urging means is measured by the displacement sensor. A sheet thickness detecting device characterized by detecting.   The paper thickness detection apparatus according to claim 3, wherein only the roller constituted by the hard member is rotated without rotating the shaft of the roller constituted by the hard member.   5. The paper thickness detection device according to claim 1, wherein a roller made of a soft member that sandwiches the paper to be conveyed is disposed inside the minimum size of the paper. Paper thickness detector.   6. The sheet thickness detection device according to claim 1, wherein a pair of rollers provided facing each other so as to sandwich a sheet to be conveyed have a required interval in each axial direction. A sheet thickness detecting device, wherein two are arranged via   7. The paper thickness detection apparatus according to claim 6, wherein the displacement sensor is provided at a position between two rollers arranged in the axial direction with a predetermined interval therebetween.   8. The sheet thickness detection device according to claim 1, wherein the urging means is provided at both ends of the shaft for detecting a displacement amount of the shaft by the displacement sensor. 9. Paper thickness detector. An image forming apparatus comprising the sheet thickness detection device according to claim 1.

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